[PATCH] clk: imx31: fix potential stack corruption on clock initialization

[PATCH] clk: imx31: fix potential stack corruption on clock initialization

[Vladimir Zapolskiy]

Function mx31_clocks_init() is called during clock intialization on
legacy boards with reference clock frequency passed as its input
argument, this can be verified by examination of the function
declaration found in arch/arm/mach-imx/common.h and actual function
users which include that header file.

Fixes: d9388c843237 ("clk: imx31: Do not call mxc_timer_init twice when booting with DT")
Signed-off-by: Vladimir Zapolskiy <vz@mleia.com>
---
 drivers/clk/imx/clk-imx31.c | 4 +---
 1 file changed, 1 insertion(+), 3 deletions(-)

diff --git a/drivers/clk/imx/clk-imx31.c b/drivers/clk/imx/clk-imx31.c
index 6a96414..6a49ba2 100644
--- a/drivers/clk/imx/clk-imx31.c
+++ b/drivers/clk/imx/clk-imx31.c
@@ -157,10 +157,8 @@ static void __init _mx31_clocks_init(unsigned long fref)
 	}
 }
 
-int __init mx31_clocks_init(void)
+int __init mx31_clocks_init(unsigned long fref)
 {
-	u32 fref = 26000000; /* default */
-
 	_mx31_clocks_init(fref);
 
 	clk_register_clkdev(clk[gpt_gate], "per", "imx-gpt.0");
-- 
2.8.1

[PATCH] clk: imx31: fix potential stack corruption on clock initialization

[Uwe Kleine-König]

On Mon, Sep 19, 2016 at 04:48:28AM +0300, Vladimir Zapolskiy wrote:
> Function mx31_clocks_init() is called during clock intialization on
> legacy boards with reference clock frequency passed as its input
> argument, this can be verified by examination of the function
> declaration found in arch/arm/mach-imx/common.h and actual function
> users which include that header file.

I don't think this can corrupt the stack. The caller puts a value in r0
that is unused by mx31_clocks_init. And given that all callers pass
26000000 there should happen nothing bad apart from a compiler warning.

So: the change is fine, IMHO the commit log shouldn't mention stack
corruption.

Best regards
Uwe

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